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S S Seshia

Publications and source records attributed to S S Seshia.

At least 19 recordsLinked to original sources
PubMed1992

Discriminant analysis when all variables are ordered.

Determination of the equation that relates an ordered dependent variable to ordered independent variables is sought. One solution, non-parametric discriminant analysis (NPD), involves obtaining the best monotonic step function by means of a computer search procedure. Although one can use alternative selection criteria in obtaining the equation, the illustrative examples use absolute distance. This paper compares the prediction procedures obtained from NPD with those from linear discriminant analysis, linear regression (with and without transformed variables), and logistic regression. We show that NPD is analogous to regression tree analysis with incorporation of ordered variables and monotonicity. We use various prediction functions to predict the example data, the data using the leave-one-out technique, and a verification set. Consistently, non-parametric discriminant analysis performs as good as or better than the tested alternatives.

Craniocerebral Trauma↗
PubMed1992

Benign neonatal sleep myoclonus. A differential diagnosis of neonatal seizures.

OBJECTIVE: To describe 10 infants with benign neonatal sleep myoclonus. DESIGN: Patient series, representing the experience of one pediatric neurologist. SETTING: Referral-based Pediatric Neurology Service at a Children's Hospital. PATIENTS: Sequential sample of 10 neonates referred for assessment of seizures and found to have benign neonatal sleep myoclonus. Neonates who did not have the events of concern during electroencephalography or in whom electroencephalography was not done were excluded even if the clinical features suggested the entity. RESULTS: Our patients met the criteria for the diagnosis. The myoclonus often increased with gentle restraint. The amplitude and duration of events mimicked convulsive status epilepticus and serial seizures in four neonates. In two of them the myoclonus worsened in spite of anticonvulsant therapy, decreasing substantially when such treatment was stopped. CONCLUSION: Benign neonatal sleep myoclonus, an entity characterized by (1) neonatal onset, (2) myoclonic jerks only during sleep, (3) abrupt and consistent cessation with arousal, (4) absence of concomitant electrographic changes suggestive of seizures, and (5) good outcome must be included in the differential diagnosis of neonatal seizures.

Diagnosis, Differential↗
PubMed1992

Atypical features of the hepatic form of carnitine palmitoyltransferase deficiency in a Hutterite family.

We describe hepatic carnitine palmitoyltransferase (CPT I) deficiency in three children (a brother and sister and their second cousin) from an extended inbred Hutterite kindred. The patients were first seen between 8 and 18 months of age with recurrent episodes of hypoketotic hypoglycemia accompanied by a decreased level of consciousness and hepatomegaly. One patient had two Reye syndrome-like episodes. Abnormal organic acids were rarely detected in urine. Serum total and free carnitine levels were elevated in all three patients. Fibroblast acyl-coenzyme A dehydrogenase activities were normal in all, but palmitic acid oxidation, performed in fibroblasts from one patient, was less than 10% of control values. Activity of CPT I in cultured skin fibroblasts from the three patients was 10% to 15% of control levels; CPT II activity was normal. Activity of CPT I and CPT II in muscle from one patient was normal. Atypical features in two of these patients were greatly elevated levels of liver enzymes and creatine kinase during acute episodes. The patients have recently been successfully treated with medium-chain triglycerides and avoidance of fasting. Early identification and treatment of this disorder may avert potentially fatal episodes of hypoglycemia.

Carnitine O-Palmitoyltransferase↗
PubMed1991

Phenotypic variability in glutaric aciduria type I: Report of fourteen cases in five Canadian Indian kindreds.

We describe 14 patients with glutaric aciduria type 1 in five Canadian Indian kindreds living in Manitoba and northwest Ontario. The patients had marked clinical variability of the disease, even within families. Eight followed the typical clinical course of normal early growth and development until the onset of neurologic abnormalities, often precipitated by infection, between 6 weeks and 7 1/2 months of age. Five patients had early developmental delay; one was thought to be normal until 8 years of age. Three patients died, seven are severely mentally and physically handicapped, and four have only mild mental retardation or incoordination. Six patients had macrocephaly in the neonatal period. Computed tomography was done for 12 patients, and findings were abnormal in 11. Glutaric acid and 3-hydroxyglutaric acid were detected in increased amounts in the urine of all patients, but the concentrations were much lower than those in most other reported patients. Glutaryl coenzyme A dehydrogenase activity in skin fibroblasts, interleukin-2-dependent lymphocytes, or both, ranged from 0% to 13% of control values. There was no correlation between clinical severity and urine glutaric acid concentration or level of residual enzyme activity. We recommend that organic acid analysis of the urine be done in patients with unexplained cerebral palsy-like disorders, especially if the computed tomographic scan is abnormal. If there is suspicion of glutaric aciduria, glutaryl-coenzyme A dehydrogenase should be measured in fibroblasts or lymphocytes even if glutaric acid is not increased in the urine.

Adult↗
PubMed1991

Inter-observer agreement in assessing comatose children.

Inter-observer agreement was evaluated for twelve items used in the neurological assessment of comatose children. Data were obtained prospectively on fifteen patients examined independently by two observers in a double-blind fashion. Observer variability was measured by using the Disagreement Rate and Kappa statistic. The Disagreement Rate ranged from 0.01 to 0.12 for all items. Values for Kappa statistic were generally in accordance with those for Disagreement Rate. The data suggest fair to almost perfect inter-observer agreement for the items used to assess comatose children in this study.

Adolescent↗
PubMed1991

Electrical status epilepticus during slow-wave sleep: a review.

Electrical status epilepticus during sleep (ESES) is primarily an EEG-defined syndrome in children characterized by the occurrence of continuous spike and slow waves during non-rapid-eye-movement (non-REM) sleep, the paroxysmal abnormalities being substantially less frequent during the awake state and REM sleep. Etiologically, cases can be divided into symptomatic and cryptogenic varieties. Partial motor seizures, frequently nocturnal, precede the emergence of ESES, whereas absence seizures often occur during the phase of ESES. The emergence of ESES is associated with neuropsychological regression. The characteristic electrographic pattern and epilepsy generally disappear during adolescence and are associated with an improvement in neuropsychological function. However, if the cases reported in the literature are representative, then there is a high probability of considerable residual dysfunction. A number of factors, broadly termed ascertainment biases, likely contribute to the paucity of reports from North America and the greater recognition of the syndrome in Europe and Japan. The current information on ESES is critiqued in this review.

Child↗
PubMed1990

Coma scales in pediatric practice.

Interobserver variability for six coma scales was assessed prospectively on a sample of 15 comatose children, by two physicians, in a double-blind fashion. The six scales were the Glasgow Coma Scale, the Simpson and Reilly Scale, the Children's Coma Score, the Children's Orthopedic Hospital and Medical Center Scale, the Jacobi Scale, and the 0 to IV Scale. Interobserver variability was measured by using disagreement rate and the kappa statistic. The results from both methods were generally concordant. The disagreement rate for the various items in the different scales ranged from a high of 0.20 to a low of 0.03. The disagreement rate was greater than 0.10 for verbal responses in the Children's Coma Score and Glasgow Coma Scale and for both items in the Children's Orthopedic Hospital and Medical Center Scale. The disagreement rate was 0.10 or less for the 0 to IV Scale and for all items in the Simpson and Reilly and Jacobi scales. The relatively high interobserver agreement for these scales makes them more suitable for the pediatric setting than the other three scales, since good agreement is essential for interpreting data reliably, both in clinical practice and for research.

Adolescent↗
PubMed1990

Myopathy with hypophosphatasia.

Three children with hypophosphatasia also had muscle pains, stiffness, and symptoms of proximal lower limb muscle weakness that occurred early in the disorder and were the presenting features in two. A non-progressive myopathy may be an important sign of hypophosphatasia.

Child, Preschool↗
PubMed1989

Automated rule based graded analysis of ambulatory cassette EEGs.

We describe algorithms, developed on a PDP-11/73 microcomputer, which identify spikes/sharp waves (STs), spike-and-wave complexes (SSWs), artifacts and background activity in 4-channel ambulatory EEGs. The algorithms were trained using 40 database segments. Time domain/mimetic methods were used and semantic rules, based on morphology and multi-channel contextual information, were developed to mimic the principles used in visual interpretation. The likelihood of STs/SSWs being genuine was graded from 10 to 1. This approach avoids forced classification of each event as genuine ST/SSW or not. The algorithms were then evaluated using 60 independent segments. STs/SSWs graded greater than 7 had significantly higher probability (P less than 0.005) of being genuine than those graded less than or equal to 7. Less than 4% of STs/SSWs identified by both electroencephalographers were missed. None was distinct. All 113 artifacts resembling STs/WWs were graded less than or equal to 7. Classification of 969/1117 (86%) waves in the background matched that of one electroencephalographer. The algorithms can be extended to 8- or more-channel EEGs.

Algorithms↗
PubMed1988

Sublingual lorazepam in childhood serial seizures.

Sublingual lorazepam was successful in controlling serial seizures in ten children. There was both intrasubject and intersubject variability in the effective dose, which ranged from about 0.05 mg/kg to 0.15 mg/kg. Side effects were minimal and consisted of drowsiness, unsteadiness, nausea, and hyperactivity. Sublingual lorazepam is an easy and effective way to treat serial seizures at home.

Administration, Sublingual↗
PubMed1988

Filtering characteristics of ambulatory EEG recording systems.

An analysis of the filtering in ambulatory EEG systems is performed. The typical ambulatory EEG system has 3 cascaded time constants each of which distorts the signal. Using a settling time criterion the analysis suggests settings or specifications for the 3 time constants in order to be equivalent to a single overall time constant. The signal distortions due to various settings are illustrated for typical EEG wave forms. It is shown that the distortion can be particularly severe when overload occurs in the ambulatory recording system, a condition that is prevalent due to high amplitude signals such as movement artifact and eyeblink.

Ambulatory Care↗
PubMed1988

CT-scan findings in an infant with glutaric aciduria type I.

An infant presented at three weeks of age with a rapidly enlarging head and hypertonicity. The diagnosis of glutaric aciduria type I (GAI) was confirmed by the absence of the enzyme glutaryl-CoA dehydrogenase in fibroblast culture. A CT scan at that time showed diffuse attenuation of cerebral white-matter. Scans at five and 10 months of age showed loss of white-matter volume and diffuse cerebral atrophy, most prominent in the frontal and temporal regions. GAI should be considered in the differential diagnosis of infants and children with neurological dysfunction who have CT-scan findings of white-matter attenuation and/or cerebral atrophy, most prominent in the frontal and temporal regions, and/or changes in the basal ganglia or thalamus.

Amino Acid Metabolism, Inborn Errors↗
PubMed1988

Status epilepticus in children.

We have prospectively reviewed the data on 52 children who presented with status epilepticus. Thirty-four (65%) of the 52 had not had seizures before. Children who were previously abnormal were more likely to present with partial status epilepticus or to have seizures greater than 60 minutes than those who were previously normal. The median age (24 months) of those who presented with status epilepticus was the same as that of children with seizures of shorter duration. The causes were equally distributed among the idiopathic, acute encephalopathic and chronic encephalopathic groups. Three children died and 13 (28%) were left with neurological sequelae. The outcome was favorable for those in the idiopathic category.

Anticonvulsants↗
PubMed1987

Computer database of ambulatory EEG signals.

The paper describes an ambulatory EEG database. The database contains segments of AEEGs done on 45 subjects. Each epoch (1/8th second or more) of AEEG data has been annotated into 1 of 40 classes. The classes represent background activity, paroxysmal patterns and artifacts. The majority of classes have over 200 discrete epochs. The structure is flexible enough to allow additional epochs to be readily added. The database is stored on transportable media such as digital magnetic tape or hard disk and is thus available to other researchers in the field. The database can be used to design, evaluate and compare EEG signal processing algorithms and pattern recognition systems. It can also serve as an educational medium in EEG laboratories.

Adolescent↗
PubMed1987

Involuntary movements with cerebellar tumour.

We describe a child with a cerebellar astrocytoma who presented with paroxysmal segmental rhythmic myoclonus. The movement disorder was characterized by focal onset in the left eyelid followed by a sequential march of clinical events. There were no clinical or laboratory findings to suggest brainstem infiltration or cerebral involvement. Marked clinical improvement followed tumour resection. We suggest that the cerebellar lesion was primarily responsible for the movement disorder.

Astrocytoma↗
PubMed1985

Artifacts in ambulatory cassette electroencephalograms.

Most artifacts in ambulatory electroencephalograms (AEEGs) are similar to those seen on conventional electroencephalograms (CEEGs) and can be identified as such. Some artifacts may simulate epileptiform or slow wave EEG activity and may occur asymmetrically or focally. We have described the use of a dual write-out method for identifying and detecting the source of artifacts in AEEGs. This technique has improved the quality of AEEGs and facilitated interpretation.

Adolescent↗